Johannes Kepler A short biography.Category Science Astronomy History People Kepler, JohannesJohannes Kepler. Michael Fowler,. UVa Physics. Link to Previous Lecture (TychoBrahe). Johannes Kepler was born on December 27, 1571, a premature child. http://galileoandeinstein.physics.virginia.edu/1995/lectures/kepler.html

Extractions: Michael Fowler, UVa Physics Galileo and Einstein Home Page Link to Previous Lecture (Tycho Brahe) As a seven-month child, Kepler was sickly from birth, and contracted smallpox when very young. His vision was severely defective, and he had various other illnesses fairly constantly, some of which may have been hypochondria. He took twice as long as normal children to get through elementary latin. He did a little better when he got to the higher school at Maulbronn, a school which only half a century earlier was haunted by the ill-famed Dr. Faustus (ref 2). While lecturing to his math class in Graz, contemplating some geometric figure involving concentric circles and triangles on the blackboard, Kepler suddenly realized that figures of the type shown here determine a definite fixed ratio between the sizes of the two circles, provided the triangle has all sides equal, and a different ratio of sizes will occur for a square between the two circles, another for a regular pentagon, and so on. Mysterium Cosmographicum the mystery of the universe (explained). The crucial illustration from his book is shown below, the outer sphere being the orbit of Saturn, and the central part is shown magnified at top right.

Kepler Johannes Kepler. Johannes Kepler is now chiefly remembered for discovering the threelaws of planetary motion that bear his name published in 1609 and 1619). http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Kepler.html

Extractions: Johannes Kepler is now chiefly remembered for discovering the three laws of planetary motion that bear his name published in 1609 and 1619). He also did important work in optics (1604, 1611), discovered two new regular polyhedra (1619), gave the first mathematical treatment of close packing of equal spheres (leading to an explanation of the shape of the cells of a honeycomb, 1611), gave the first proof of how logarithms worked (1624), and devised a method of finding the volumes of solids of revolution that (with hindsight!) can be seen as contributing to the development of calculus (1615, 1616). Moreover, he calculated the most exact astronomical tables hitherto known, whose continued accuracy did much to establish the truth of heliocentric astronomy ( Rudolphine Tables , Ulm, 1627).

Extractions: Kepler's teacher in the mathematical subjects was Michael Maestlin (1580-1635). Maestlin was one of the earliest astronomers to subscribe to Copernicus's heliocentric theory, although in his university lectures he taught only the Ptolemaic system. Only in what we might call graduate seminars did he acquaint his students, among whom was Kepler, with the technical details of the Copernican system. Kepler stated later that at this time he became a Copernican for "physical or, if you prefer, metaphysical reasons." In 1594 Kepler accepted an appointment as professor of mathematics at the Protestant seminary in Graz (in the Austrian province of Styria). He was also appointed district mathematician and calendar maker. Kepler remained in Graz until 1600, when all Protestants were forced to convert to Catholicism or leave the province, as part of Counter Reformation The Cosmographic Mystery , in which he argued that the distances of the planets from the Sun in the Copernican system were determined by the five regular solids, if one supposed that a planet's orbit was circumscribed about one solid and inscribed in another.

Extractions: Johannes Kepler (1571-1630) Johannes Kepler was born on December 27, 1571 in Weil der Stadt, Germany. Kepler's grandfather was supposedly from a noble background, and once Mayor of Weil. However, Kepler's father became a mercenary who narrowly avoided the gallows. Kepler's mother, Katherine, was raised by an aunt who was eventually burned as a witch. In later years, Katherine herself was accused of Devil worship, and barely escaped from being burned at the stake. Kepler had six brothers and sisters, three of which, died in infancy. In his youth, Johannes was described as: "...a sickly child, with thin limbs and a large, pasty face surrounded by dark curly hair. He was born with defective eyesight-myopia plus anocular polyopy (multiple vision). His stomach and gall bladder gave constant trouble; he suffered from boils, rashes, and possibly from piles, for he tells us that he could never sit still for any length of time..." (Koestler, p 24) From this inauspicious start, Johannes Kepler began his fascinating journey as a pioneer in astronomy. Go to Next Page Return to Table of Contents See References Last Updated November 24, 1997 by

Extractions: Johannes Kepler discovered that planets move round the Sun in elliptical orbits. He gave three mathematical laws of planetary motion. Kepler was a devout, but not completely orthodox, Lutheran. He was a convinced Platonist, which is to say that he looked for mathematical relationships in the observable universe. Kepler attended the University of Tübingen, where his mathematical ability was noticed by his astronomy teacher Michael Maestlin. Officially Maestlin taught geocentric (Ptolemaic) astronomy, but able pupils, among them Kepler, were also introduced to the heliocentric astronomy of Copernicus (published in 1543). Kepler originally intended to become a priest, but was persuaded to take up a post teaching mathematics at Graz. In 1596, Kepler published his Mysterium Cosmographicum, which argues for the truth of the Copernican system by giving a mathematical explanation of its structure (in terms of regular polyhedra). In 1600, Kepler went to Prague, as assistant to Tycho Brahe. Brahe died in 1601, but Kepler went on to use his observations to calculate planetary orbits of unprecedented accuracy.